Linkage assembly for lifting the lid of a container



Feb. 10, 1970 c. R. HILLHOUSE 3,494,219

LINKAGE ASSEMBLY FOR LIFTING THE LID OF A CONTAINER Filed Jan. 19. 1968 INVENTOR CHARLES RAY HILLHOUSE BY ATTORNEYfi United States Patent U.S. Cl. 74--469 6 Claims ABSTRACT OF THE DISCLOSURE The linkage assembly, which is preferably attached at each side of the lid, includes a pair of pivot points disposed on brackets projecting perpendicularly from the lid. Two links, each pivotally mounted at one end to the container, are each pivotally connected at the other end to an associated pivot point on the lid brackets. The pivotal mounting to the container of one of the links is provided at the outer end of a vertically projecting arm. The other link is provided by one arm of a bell crank, the other arm of which is rotated by a hydraulic ram. The ram has its opposite end pivotally connected to the container. Rotating one of the links rotates and raises the lid to bring it forwardly to an upright position.

BACKGROUND OF THE INVENTION so that there is a minimum amount of handling by an operator. This is especially true with regard to the etching process in which acid is used.

Specifically, the handling problems inherent in the etching process is solved by providing a lid, which carries a workpiece on its underside, so that when the lid is closed, the workpiece faces downward in correct proximity to the acid, and yet when the lid is in its raised, substantially upright position, the workpiece faces an operator standing in front of the machine, and is directly accessible to him at a convenient working height.

Obviously, the common type of hinged lid in which the hinge means is located along one edge of the container does not satisfy this requirement. This is particularly true if the hinge means is provided on the rear edge of the lid because when the lid is raised, the workpiece is rotated away from rather than toward the operator.

The type of lid which is pivotally mounted to the container by opposing centrally disposed pinions also suffers serious deficiencies. While this type of lid may be rotated so that the workpiece faces an operator, a large part of the lid area remains within the container and moreover, such a lid in a raised position is likely to be unstable.

The present linkage assembly rotates and raises the lid and carries the lid forwardly as the lid is rotated and raised so that the lid is in a position of maximum convenience to an operator when in the open position.

None of the known lid-lifting mechanisms accomplishes this combination of movements and result.

SUMMARY OF THE INVENTION The linkage assembly includes a lid having opposing sides, one side including a pair of pivot points disposed in spaced relation on the lid.

A first linkage means supports one side of the lid, the linkage means including a pair of links, each link being pivotally connected at one of its ends to one of the pivot points on the lid, and each link being pivotally mounted to the container at its other end. Each link relatively rotates its associated pivot points about its associated pivotal mounting on the container.

The pivotal mountings of each link to the container are disposed in spaced relation from each other, whereby rotation of one link causes rotational movement of the lid about each of the spaced pivot points on the lid simultaneously to raise or lower the lid. The limit of free angular movement of one of the pair of links occurs when the spaced pivot points are aligned with the pivotal mountings of the other link to the container. The pivotal mounting to the container of each individual link bears a fixed spaced relation from the pivotal mounting to the container of the other link.

Driving means, operatively interconnected to one of the links, selectively rotates said one link to cause rotational movement of the lid. The driving means includes an extensible arm having one end pivotally mounted to the container and having the other end operatively interconnected to one of the links. One of the links includes a transverse arm to which the extensible arm is pivotally connected.

The side of the lid supported by the linkage means includes a transverse bracket projecting from the lid and including one of the pivot points, whereby to permit wide spacing of the pivot points and thereby increase mechanical advantage of the linkage assembly.

The other side of the lid includes a complementary pair of pivot points disposed in fixed spaced relation on the lid. A second linkage means including a pair of links substantially in mirror image of the first linkage means provides a complementary linkage means supporting the other side of the lid. The features discussed above with respect to said one side of the lid occur on said other side of the lid.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the etching machine illustrating the lid of the acid container in its raised position;

FIG. 2 is a fragmentary, and elevational view illustrating the disposition of the linkage assembly when the lid is in substantially the same raised position;

FIG. 3 is a fragmentary, and elevational view illustrating the disposition of the linkage assembly when the lid is in its closed position, and

FIG. 4 is an enlarged fragmentary view taken on line 4-4 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now by characters of reference to the drawing, and first to FIG. 1, it will be understood that the lid-lifting assembly is utilized in conjunction with an etching machine 10. The lid 11 provides the closure means for an acid container 12. In FIG. 1, the disposition of the lid 11 is in a substantially upright position, the workpiece, which is attached by clips 18 and 19 to the lid underside 14, faces forwardly of the etching machine 10. The lid upperside 15, of course, faces rearwardly.

The lid 11 includes a pair of opposing sides 16, to each of which, linkage means is attached. In the preferred embodiment, the linkage assembly is substantially symmetrical, and it will be observed in FIG. 1 that there is a space between the instrument panel 17 and the container 12 so that this may be effectuated.

The linkage on one side of the lid is a mirror image of that on the other side of the lid. Therefore, for convenience, the same reference characters are given to like parts, it being understood that such parts are oppositely disposed.

FIG. 2 illustrates the disposition of the linkage assembly when the lid 11 is in its upright position. Bracket members 20 and 21 project outwardly from the lid underside 14 and the lid upperside 15 respectively, and effectively form a part of the lid. The brackets and 21 are fixedly attached to the lid 11 as by welding.

The bracket 20 includes a pivot point 22, and the bracket 21 includes a pivot point 23. Because the brackets 20 and 21 form part of the lid, the pivot points 22 and 23 are disposed in fixed, spaced relation on the lid.

The upper edge 24 of each side 25 of the container 12 is reinforced by an elongate stiffener 26. The stiffener 26 extends between the front and rear portions of the acid container 12. The side 25 of the acid container 12 includes an upwardly projecting post member 27.

A link 30 is pivotally mounted at one end to the container 12 at the forward end of the stiifener 26, a pivotal connection 32 being provided for this purpose. Similarly a link 31 is pivotally mounted at one end to the upper end of the post 27, a pivotal connection 33 being provided at this location. The points of pivotal connection 32 and 33 of the links 30 and 31 to the container 12 bear a fixed, spaced relation to each other.

The links 30 and 31 are pivotally connected to the lid 11 at their other ends at pivot points 22 and 23 respectively. The lid 11 itself thereby forms a link interconnecting links 30 and 31.

The link 30 is provided by one arm of a bell crank 34, the other transverse arm 35 of the bell crank 34 is operatively, pivotally interconnected to a driving means provided by a hydraulic cylinder 36.

The link 31 is provided by a rod 37 which is threadedly attached to a stub axle 40. The stub axle 40 being rotatively connected to the bracket 21. This latter connection is clearly shown in FIG. 4. It will be understood that the connection of the other end of the link 31 to the pivotal mounting 33 is accomplished in a like manner. This threaded rod connection provides a link 31 which is adjustable in its length, and this adjustment may be utilized to provide a fine adjustment feature for the linkage assembly as a whole.

Any conventional pin or fastener may be utilized to form the other pivotal connections such as those at 22 and 32 and it is not believed necessary to describe these in detail.

The drive means in the preferred example comprises a hydraulic cylinder 36 having an extensible ram 41. Broadly, the cylinder 36 and ram 41 constitute an extensible arm. A pivotal connection 42 is provided at the outer end of the ram 41, which interconnects the transverse arm 35 of the bell crank 34. The opposite end of the hydraulic cylinder 36 is pivotally mounted to the stiffener 26, by a pivot means 43. FIG. 3 shows the ram 41 in its extended position, in which position it will be clear that the lid 11 is closed.

It will be understood that the greater the distance between lid pivot points 22 and 23, the greater will be the leverage applied to turning the lid 11. Hence, the provision of brackets 20 and 21 provides a means of conveniently elfectuating an increase in this distance, and hence a means of increasing the mechanical advantage of the system.

It is thought that the functional advantages of this lidlifting assembly have become fully apparent from the foregoing description of parts, but for completeness of disclosure the operation of the assembly will be briefly described, and the relationship between the various links discussed in more detail.

The link 30 is pivotally mounted at one end to the container 12. The link 30 may be rotated about the container pivotal mounting 32 so that the pivot point 22 at the other end of the link 30 describes an are having a radius equal to the distance between pivotal centers 22 and 32.

The lid 11, including the projecting brackets 20 and 21, in effect provides a link interconnecting the links 30 and 31. The theoretical line of action of this link is 4 indicated by the phantom line 44 in both FIGS. 2 and 3. This line 44 is used as a reference for clarity to indicate the link.

In the preferred embodiment, as may be observed from FIG. 2, counter-clockwise rotation of the link 30 will cause the lid 11 to rotate in a clockwise direction about the pivot point 22 and in a clockwise direction about the pivot point 23. Continuation of this rotation of link 30 will rotate the lid 11 in a substantially clockwise direction, moving the lid 11 downwardly at the same time until the lid 11 is in its closed position as indicated in FIG. 3. The effect of this rotary motion of the link 30 is to rotate the link 44 and cause its mid-point to move both horizontally and vertically. Obviously, this continuous rotary motion is conveniently accomplished by applying a force from the extensible ram 41 to the transverse arm 35 of the bell crank 34.

Certain relationships exist between the links which assist in defining the linkage assembly, As a practical matter, stop means are provided to prevent complete cyclic motion of the link 30, the stop means in the present embodiment being provided by the limited traverse of the extension ram 41 and by the closing action of the lid. However, if the link 30 were allowed to rotate freely in a clockwise direction, for example, the limit of this free angular movement would occur when the spaced pivot points 22 and 23 were aligned directly with the fixed pivot point 33. By the same token, the limit of the free angular movement of the link 31 in a counterclockwise direction would be attained when the pivot points 22 and 23 were directly aligned with the fixed pivotal mounting 32.

The limit of free angular movement of one link may also be defined as occurring when the pivotal connection of the lid 11 to that link forms the apex of a triangle, the triangle having one side equal to the length of that link, and an adjacent side equal to the sum of the lengths of the other link and the hypothetical link 44. The base of this triangle, is equal to the fixed distance between the pivotal connections 32 and 33. It is understood that the length of a link is defined as the length between pivotal points on that particular link.

The relationships discussed above are, it will be understood, cyclical and symmetrical in that if the links 30, 31 and the hypothetical link 44 were allowed to move freely, the cycle of movement would be symmetrical above and below a hypothetical base line interconnecting the pivotal connections 32 and 33.

When the lid 11 is raised, the lid 11 will move upwardly toward the front of the container 12 and will simultaneously rotate to place the workpiece 13 within easy reach of the operator standing at the front of the machine. This movement is seen from a comparison of FIGS. 3 and 2.

I claim as my invention:

1. A linkage assembly for lifting the lid of a container, the linkage assembly comprising:

(a) a lid having a pair of opposing sides, at least one side including a pair of pivot points disposed in fixed, spaced relation on the lid,

(b) linkage means including:

(1) a first link pivotally connected at one end to one of said pivot points on the lid, the other end of the link being adapted to be pivotally mounted to the container to rotate said pivot point relatively about the pivotal mounting,

(2) a second link pivotally connected at one end to the other of said pivot points on the lid, the other end of the link being adapted to be pivotally mounted to the container to rotate said other pivot point relatively about the last said pivotal mounting, and

(c) the pivotal mountings of the first and second links being disposed in spaced relation form each other a greater distance than the spaced pivot points on the lid.

2. A linkage assembly as defined in claim 1, in which:

(d) the lid includes an underside and an upper side,

and

(e) one of the pivot points is relatively disposed upper side of the lid and the other of the pivot points is relatively disposed underside of the lid so that the lid lies transversely of a line connecting the pivot points.

3. A linkage assembly as defined in claim 1, in which:

(d) driving means is operatively interconnected to one of the links, and selectively rotates said link in one direction to cause rotational movement of the lid from a substantially horizontal to a substantially upright position.

4. A linkage assembly as defined in claim 1, in which:

(d) one of the links includes a transverse arm providing a bell crank, and

(e) driving means, adapted to be mounted on the container, is operatively interconnected to the transverse arm whereby to selectively rotate said link to cause rotational movement of the lid.

5. A linkage assembly, as defined in claim '1, in which:

(d) said one side of the lid includes a transverse bracket, the transverse bracket projecting from the lid and including one of the pivot points whereby to permit wide spacing of the pivot points and thereby increase the mechanical advantage of the linkage assembly, and

(e) an extensible arm, having one end adapted to be pivotally mounted on the container and having the other end operatively interconnected to one of the links, selectively rotates said link to cause rotational movement of the lid.

6. A linkage assembly as defined in claim 1, in which:

(d) the other side of the lid includes a complementary pair of pivot points disposed in fixed, spaced relation on the lid, and

(e) a second linkage means including a first link and a second link substantially in mirror image of the first linkage means and related to said other side of the lid, as the first linkage means is related to said one side of the lid, provides, a complementary linkage means supporting said other side of the lid.

References Cited UNITED STATES PATENTS 1,009,488 11/1911 Dombrink 49--339 X MILTON KAUFMAN, Primary Examiner US. Cl. X.R. 

